Oral Presentation ANZOS-OSSANZ-AOCO Joint Annual Scientific Meeting 2017

Cortical inputs to the lateral hypothalamus influence body weight and food choice   (#134)

Rachel Clarke 1 , Moyra B Lemus 1 , Sarah H Lockie 1 , Zane B Andrews 1
  1. Department of Physiology, Monash University, Melbourne, VIC, Australia

Food choices are influenced by both metabolic need and hedonic motivation. The lateral hypothalamus (LH) is uniquely positioned to receive information related to both internal metabolic status and external cues. How the LH balances homeostatic and hedonic inputs to coordinate feeding and motivated behaviour has not yet been fully elucidated. The cortical regions of the brain including the orbital frontal cortex (OFC) and the anterior cingulate cortex (ACC) are understood to be involved in decision-making processes surrounding food and food reward. Anatomical tracing studies demonstrate monosynaptic projections from the OFC and ACC to the LH.  However, whether these circuits are functionally relevant to feeding and motivated behaviours has not yet been explored. In this study, a dual-viral transgenic approach was used to ablate OFC-LH and ACC-LH pathways in separate cohorts of C57BL/6 mice. Ablation of the OFC-LH pathway resulted in increased bodyweight on a chow diet (p=0.033). While ablation of the ACC-LH pathway resulted increased bodyweight on a high fat diet (HFD) (p=0.013). A battery of behavioural tests were used to investigate a potential role for this circuit in anxiety, risk-reward processing and hedonic aspects of feeding. Mice with OFC-LH pathway ablation tended to consume more HFD than controls over three-days of ad lib access to both chow and HFD (p=0.049). Results so far suggest these cortical-LH pathways influence food choices and body weight.